src/java/org/apache/poi/poifs/filesystem/DirectoryNode.java

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache POI" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
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 *
 * 5. Products derived from this software may not be called "Apache",
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 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.poi.poifs.filesystem;

import java.io.*;

import java.util.*;

import org.apache.poi.hpsf.ClassID;
import org.apache.poi.poifs.dev.POIFSViewable;
import org.apache.poi.poifs.property.DirectoryProperty;
import org.apache.poi.poifs.property.DocumentProperty;
import org.apache.poi.poifs.property.Property;

/**
 * Simple implementation of DirectoryEntry
 *
 * @author Marc Johnson (mjohnson at apache dot org)
 */

public class DirectoryNode
    extends EntryNode
    implements DirectoryEntry, POIFSViewable
{

    // Map of Entry instances, keyed by their names
    private Map               _entries;

    // the POIFSFileSystem we belong to
    private POIFSFileSystem   _filesystem;

    // the path described by this document
    private POIFSDocumentPath _path;

    /**
     * create a DirectoryNode. This method is not public by design; it
     * is intended strictly for the internal use of this package
     *
     * @param property the DirectoryProperty for this DirectoryEntry
     * @param filesystem the POIFSFileSystem we belong to
     * @param parent the parent of this entry
     */

    DirectoryNode(final DirectoryProperty property,
                  final POIFSFileSystem filesystem,
                  final DirectoryNode parent)
    {
        super(property, parent);
        if (parent == null)
        {
            _path = new POIFSDocumentPath();
        }
        else
        {
            _path = new POIFSDocumentPath(parent._path, new String[]
            {
                property.getName()
            });
        }
        _filesystem = filesystem;
        _entries    = new HashMap();
        Iterator iter = property.getChildren();

        while (iter.hasNext())
        {
            Property child     = ( Property ) iter.next();
            Entry    childNode = null;

            if (child.isDirectory())
            {
                childNode = new DirectoryNode(( DirectoryProperty ) child,
                                              _filesystem, this);
            }
            else
            {
                childNode = new DocumentNode(( DocumentProperty ) child,
                                             this);
            }
            _entries.put(childNode.getName(), childNode);
        }
    }

    /**
     * @return this directory's path representation
     */

    public POIFSDocumentPath getPath()
    {
        return _path;
    }

    /**
     * create a new DocumentEntry
     *
     * @param document the new document
     *
     * @return the new DocumentEntry
     *
     * @exception IOException
     */

    DocumentEntry createDocument(final POIFSDocument document)
        throws IOException
    {
        DocumentProperty property = document.getDocumentProperty();
        DocumentNode     rval     = new DocumentNode(property, this);

        (( DirectoryProperty ) getProperty()).addChild(property);
        _filesystem.addDocument(document);
        _entries.put(property.getName(), rval);
        return rval;
    }

    /**
     * Change a contained Entry's name
     *
     * @param oldName the original name
     * @param newName the new name
     *
     * @return true if the operation succeeded, else false
     */

    boolean changeName(final String oldName, final String newName)
    {
        boolean   rval  = false;
        EntryNode child = ( EntryNode ) _entries.get(oldName);

        if (child != null)
        {
            rval = (( DirectoryProperty ) getProperty())
                .changeName(child.getProperty(), newName);
            if (rval)
            {
                _entries.remove(oldName);
                _entries.put(child.getProperty().getName(), child);
            }
        }
        return rval;
    }

    /**
     * Delete an entry
     *
     * @param entry the EntryNode to be deleted
     *
     * @return true if the entry was deleted, else false
     */

    boolean deleteEntry(final EntryNode entry)
    {
        boolean rval =
            (( DirectoryProperty ) getProperty())
                .deleteChild(entry.getProperty());

        if (rval)
        {
            _entries.remove(entry.getName());
            _filesystem.remove(entry);
        }
        return rval;
    }

    /* ********** START implementation of DirectoryEntry ********** */

    /**
     * get an iterator of the Entry instances contained directly in
     * this instance (in other words, children only; no grandchildren
     * etc.)
     *
     * @return iterator; never null, but hasNext() may return false
     *         immediately (i.e., this DirectoryEntry is empty). All
     *         objects retrieved by next() are guaranteed to be
     *         implementations of Entry.
     */

    public Iterator getEntries()
    {
        return _entries.values().iterator();
    }

    /**
     * is this DirectoryEntry empty?
     *
     * @return true if this instance contains no Entry instances
     */

    public boolean isEmpty()
    {
        return _entries.isEmpty();
    }

    /**
     * find out how many Entry instances are contained directly within
     * this DirectoryEntry
     *
     * @return number of immediately (no grandchildren etc.) contained
     *         Entry instances
     */

    public int getEntryCount()
    {
        return _entries.size();
    }

    /**
     * get a specified Entry by name
     *
     * @param name the name of the Entry to obtain.
     *
     * @return the specified Entry, if it is directly contained in
     *         this DirectoryEntry
     *
     * @exception FileNotFoundException if no Entry with the specified
     *            name exists in this DirectoryEntry
     */

    public Entry getEntry(final String name)
        throws FileNotFoundException
    {
        Entry rval = null;

        if (name != null)
        {
            rval = ( Entry ) _entries.get(name);
        }
        if (rval == null)
        {

            // either a null name was given, or there is no such name
            throw new FileNotFoundException("no such entry: \"" + name
                                            + "\"");
        }
        return rval;
    }

    /**
     * create a new DocumentEntry
     *
     * @param name the name of the new DocumentEntry
     * @param stream the InputStream from which to create the new
     *               DocumentEntry
     *
     * @return the new DocumentEntry
     *
     * @exception IOException
     */

    public DocumentEntry createDocument(final String name,
                                        final InputStream stream)
        throws IOException
    {
        return createDocument(new POIFSDocument(name, stream));
    }

    /**
     * create a new DocumentEntry; the data will be provided later
     *
     * @param name the name of the new DocumentEntry
     * @param size the size of the new DocumentEntry
     * @param writer the writer of the new DocumentEntry
     *
     * @return the new DocumentEntry
     *
     * @exception IOException
     */

    public DocumentEntry createDocument(final String name, final int size,
                                        final POIFSWriterListener writer)
        throws IOException
    {
        return createDocument(new POIFSDocument(name, size, _path, writer));
    }

    /**
     * create a new DirectoryEntry
     *
     * @param name the name of the new DirectoryEntry
     *
     * @return the new DirectoryEntry
     *
     * @exception IOException
     */

    public DirectoryEntry createDirectory(final String name)
        throws IOException
    {
        DirectoryProperty property = new DirectoryProperty(name);
        DirectoryNode     rval     = new DirectoryNode(property, _filesystem,
                                         this);

        (( DirectoryProperty ) getProperty()).addChild(property);
        _filesystem.addDirectory(property);
        _entries.put(name, rval);
        return rval;
    }

    /**
     * Gets the storage clsid of the directory entry
     *
     * @return storage Class ID
     */
    public ClassID getStorageClsid()
    {
        return getProperty().getStorageClsid();
    }

    /**
     * Sets the storage clsid for the directory entry
     *
     * @param clsidStorage storage Class ID
     */
    public void setStorageClsid(ClassID clsidStorage)
    {
        getProperty().setStorageClsid(clsidStorage);
    }

    /* **********  END  implementation of DirectoryEntry ********** */
    /* ********** START implementation of Entry ********** */

    /**
     * is this a DirectoryEntry?
     *
     * @return true if the Entry is a DirectoryEntry, else false
     */

    public boolean isDirectoryEntry()
    {
        return true;
    }

    /* **********  END  implementation of Entry ********** */
    /* ********** START extension of Entry ********** */

    /**
     * extensions use this method to verify internal rules regarding
     * deletion of the underlying store.
     *
     * @return true if it's ok to delete the underlying store, else
     *         false
     */

    protected boolean isDeleteOK()
    {

        // if this directory is empty, we can delete it
        return isEmpty();
    }

    /* **********  END  extension of Entry ********** */
    /* ********** START begin implementation of POIFSViewable ********** */

    /**
     * Get an array of objects, some of which may implement
     * POIFSViewable
     *
     * @return an array of Object; may not be null, but may be empty
     */

    public Object [] getViewableArray()
    {
        return new Object[ 0 ];
    }

    /**
     * Get an Iterator of objects, some of which may implement
     * POIFSViewable
     *
     * @return an Iterator; may not be null, but may have an empty
     * back end store
     */

    public Iterator getViewableIterator()
    {
        List components = new ArrayList();

        components.add(getProperty());
        SortedMap sortedEntries = new TreeMap(_entries);
        Iterator  iter          = sortedEntries.values().iterator();

        while (iter.hasNext())
        {
            components.add(iter.next());
        }
        return components.iterator();
    }

    /**
     * Give viewers a hint as to whether to call getViewableArray or
     * getViewableIterator
     *
     * @return true if a viewer should call getViewableArray, false if
     *         a viewer should call getViewableIterator
     */

    public boolean preferArray()
    {
        return false;
    }

    /**
     * Provides a short description of the object, to be used when a
     * POIFSViewable object has not provided its contents.
     *
     * @return short description
     */

    public String getShortDescription()
    {
        return getName();
    }

    /* **********  END  begin implementation of POIFSViewable ********** */
}   // end public class DirectoryNode